What you will need:
• Welder/ oxygen/acetylene set
• Leather welding gloves
• Enclosed shoes (preferably leather)
• Long shirt and pants
• Welding rods
• Welders helmet
• Scrap steel
• Vice (to hold sculpture)
• Wire brush
• Chipping hammer
• Tin snips
• Angle grinder (optional)
Step 1: Choosing Your Sculpture
Step 2: Gather Materials and Tools
Step 3: Arc Welding
Step: 3.1.1 Understanding an arc welder
An arc welder works by passing a current through an electrode which jumps via an air gap onto the grounded metal and melting the tip of the rod due to high current and heat, therefore welding the surface.
Step: 3.1.2 Preparing the welding surface
The easiest way to clean up a welding surface is to use an angle grinder. But if you do not have one, sandpaper will be fine and a wire brush to clean up the gaps. Remove paint and rust if any.
Step: 3.1.3 Setting your welding machine
You will have to set your welding machine to the correct amperage so that you can create a good quality weld. A machine set too high will just make a lot of spattered welds and melt the grounded metal too much. A machine set too low will make the electrode stick to the grounded metal and will not provide a highly penetrated weld. How high you will need to set your machine will depend on what welding electrodes you have. (Guide located at the bottom of document)
Step: 3.1.3 Striking an arc
To start an arc, you have to strike the rod like you are playing pool, the rod must scrape along the grounded metal. Soon you will see an arc of light, to continue this arc you have to allow the rod and the grounded metal an air gap, so enough heat is produced to melt the rod and fuse the metal.
Step: 3.1.4 Making a bead
When you are welding you must move the electrode to make a bead, beads can be shaped by moving the rod in a different pattern. Some popular patterns are; the crescent and the zigzag.
Step: 3.1.5 Removing slag
After you have completed a bead, you will have a layer of slag, you can chip this off with the chipping hammer and use the wire brush to remove the carbon from welding.
IMPORTANT! : After each bead, chip off and clean up the weld before starting another bead.
Step: 3.1.6 Testing weld quality
Depending on what part of the sculpture you are welding on, you will have to test its strength, to do this you have to try and move it with your hands, if you cannot break it off it is strong enough. You do not have to make it super strong because it is only for decorative purposes.
Step: 3.1.7 Danger
Do not weld with an arc welder if the piece of metal, the electrode or your gloves are wet. This may cause an electrocution.
Do not touch your work piece for at least 5 minutes without gloves because it will remain hot for quite some time.
Arc welding will cause pieces of hot metal to “pop” in every direction, make sure that there are no flammable materials are around.
Step 4: Oxygen-Acetylene Welding
An oxygen/acetylene set (or oxy set for short) works by combining 2 gases (oxygen and acetylene) with different mixtures into a hose then coming out of a welding nozzle, which has to be lighten by a striker. The welding nozzles that you can get vary from 000 (thin metal welding) to 3 (thick metal welding).
Step: 3.2.2 What you will need
You will need; an oxygen cylinder, acetylene cylinder, regulators and hoses for each, welding torch with welding nozzles (around 000), welding goggles and a striker (to light the torch)
Step: 3.2.3 Setting the levels
When welding with an oxy set, you will have to adjust the amount of gas coming out. To do this you will need to use the taps near the gas cylinders. Firstly, you open the acetylene cylinder by turning the tap ½ of a turn. Set the acetylene regulator for 5 psi, open the pin valve on the torch to let acetylene escape. Tweak the regulator until the acetylene is at a solid 5 psi, then close the pin valve. Open the main oxygen valve fully, and then adjust the oxygen regulator to 10 psi. let it settle and continue to adjust it to maintain 10psi, close the pin valve for oxygen. Open the acetylene valve approx. 1/8th of a turn and then use the striker to light the acetylene gas.
Step: 3.2.4 Preparing the flame
Continue to release the acetylene until the flame is about to leave the tip of the welding torch, slowly open the oxygen pin and set it to a neutral flame. A neutral flame is where you have equal parts oxygen to acetylene. The middle blue section will merge into the whitish blue section, this is the neutral flame.
Step: 3.2.5 Welding with the oxy set
When you have prepared the flame, prepared your surfaces and have your safety equipment on you are ready to weld. You have to use the middle blue section of the flame to weld; this section must touch your work piece. Continue to heat up the 2 surfaces of metal until you have a pool forming on both parts. This pool should merge into one, if this does not happen continue to heat the unmelted piece. Once this has happened, you have to use the flame to stir the 2 pools together, this will form the weld. Once you have finished the weld, turn off the oxygen pin valve first, then the acetylene valve.
Step: 3.2.6 Dangers
Because an oxy set uses oxygen, there are huge dangers of things being set alight. Oxygen speeds up the process of things burning and could become deadly.
When welding with an oxy set, the work piece can retain its heat for a long time, due to the heat delivered from welding. This can be dangerous if you do not have leather gloves.
Backfires: a backfire will cause the flame to shoot up into the nozzle and is stopped at the arrestor; this will cause a loud bang.
Flashbacks: flashbacks are like backfires but the can carry up into the tubes of the tanks, the oxygen torch should be turned off first then the acetylene torch valve, Followed by the oxygen tank valve and lastly, the acetylene tank valve.
When welding, you may experience a pool or droplet of molten steel to fall off the work piece. This will splash and may send hot pieces everywhere. Make sure that there are no flammable materials around.
Step 5: Base Building
Step 6: Sculpting Your Sculpture
Step 7: Add Ons
Step 8: Reviewing
Step 9: Finishing
• Rusty steel
• Hammer tone paint
Once painted, you have a nice-looking, homemade sculpture for the garden or on display in the home.
Step 10: References
• http://www.wikihow.com/Arc-Weld -- used to help with steps of welding 05/02/12 Last edited: September 23, 2011 by Elocina
• http://www.stanford.edu/group/prl/documents/html/OAweld.htm -- used for the oxy welding processes 05/02/12
revision history :
Ver 1.0 -- 5/97 -- Steve Johnson -- original text
Ver 1.1 -- 6/97 -- Bryan Cooperrider -- formatting, revisions, and additions
Ver 1.2 -- 10/01 -- Katherine Kuchenbecer -- minor revisions.
• http://www.tcforensic.com.au/docs/uts/essay4.pdf -- used for the dangers of welding (gas and arc) 05/02/12
• http://desiredcreations.com/howto_tllittletorch.htm -- used for picture of neutral flame 07/02/12
• http://www.oxyacetylenetanks.info/ -- oxy torch set picture 06/02/12
This "how-to" was uploaded as a part of the year 12 research project for the SACE.